Gripper for offset printing presses



Oct. 26 1926.

w. GEGENHEIMER ET AL.

GRIPPER FOR OFFSET PRINTING PRESSES Filed Dec. 5. i925 INVENTOR z E5 /3W7 j I v AQJLM AT NEY Patented Get. 26, 1925.

rent 41..

WILLIAM enennnnnvrnn, or BALDWIN, AND ERNEST n. BARNEY, or ronrwssnmeroinnnw YORK. V

GRIPPER FOR OFFSET PRINTING PRESSES.

Application filed December 5, 1925. Serial No. 78,390

This invention relates to gripper mechanism for removing a printed sheet from the impression or fced cylinder of a press, par ticularly an offset press. In such apparatus a plurality of fingers are employed to periodically seize the sheets as the impressions are completed thereon during the rotation of the feed cylinder, the sheets being removed from the latter and carried to the stack.

in the usual types of such gripper mechanism, the fingers are carried by a grippershaft arranging parallel with a, so-called saddle-shaft having projections in register with the lingers so that the sheet is seized between the fingers and the said projections. lhe gripper-shaft is oscillated by acam when the fingers come into register with the sheet so that the fingers are moved into contact with the latter, a reverse oscillation of the shaft taking place when the sheet is released, at the stack.

Gusto-mainly, the gripper shaftis springactuated to carry the fingersioward the projections of the saddle shaft. A recognized necessity in such case is exact adjust ment of the lingers upon the gripper-shaftso that none of the fingers shall be in advance of other fingers ofthe set, because, in such case, the lasted named fingers would be inactive or only partially active, that is to say they would not grip the paper or would grip the paper with insuflicient force. Another difiiculty is that even when the fingers are adjusted to exact position, the spring of the saddle-shaft itself orthe grippershaft is frequently such that some of the fingers received the full tension of the gripper-shaft spring to the exclusion'of other fingers and the sheet is unevenly pulled and frequently torn. Y

Attempts have" been made to impel the fingers'by means of springs acting supplementary to the gripper shaft spring, but this has not solved the diificulty, because such springs have acted tov neutralize the effect of the gripper-shaft spring and exact adj ustment of the fingers still is necessary, which adjustment is in practice seldom achieved for various reasons including the spring ing of thesaddle-shaft from the centre towards its ends through the pressure of the fingers. Theobject of the present invention is to overcome the various stated defects in gripper mechanism,

The invention will be understood by ref-' erence to the accompanying drawings in which-' Figure 1 is aplan View of associated gripper and saddle shafts and other gripper elements, two gripper fingers being shown, and

Figure 2 is a transverse section on the line 2-2, Figure 1.

Referring to the drawings, the grippershaft A is shown with part ofits length broken away and two grippingfingers only mounted thereon. The gripper shaft is mounted in the bearings l and 1t 1s parallel with the saddle-shaft B journaleol in bear ings '2, the saddle-shaft also being showir broken, away. Thesaddle-shraft is provided with the projections or saddles 3in registerwith the gripper fingers 4. Each gripper finger is formed as a curved projection from a circular base a, which partially encircles, and is mounted upon, the gripper-shaft A forfree oscillation thereon. The base 4* of the gripper finger is placed intermediate the two spaced. halves of an actuating sleeve 5,.

the said halves being joined by a head C providlng an upper shoulder 0* and a lower shoulder 0 adapted to contact with the crum plate 8 secured by screw stud, 9"to the saddle-shaft B. A, spring encircles link rod- 7 and bears againstfulcrum plate 8, the tension of the spring being regulated by anut 10 threaded upon the link rod.

The actlon of the spring in bearing upon fulcrum plate 8, which is fixed and rigid, is such that the tension of the spring is thrown upon the link rod through nut 10 and the rod acts to move the gripper finger in the direction of the arrow, Figure 2. I g

In Figure 2 of the drawings the parts are shown in the active'position of the gripper fingers and it will be seen; that the gripping functions of the latter are entirely independent of the gripper shaft. When the moment for release of the sheet is reached, the gripper shaft is rotated counter-clockwise and carries with it the actuating sleeve, by reason of the fact that the head of the latter is fixed upon the shaft by means of screw able free and unhampered action of the spring 12, and thus the gripper-shaft has a slight counter-clockwise turn before shoulder 0 reaches the base of the finger and then turns the linger with the shaft, raising it from the saddle and the sheet theretofore gripped. p

In our improvements the gripper-shaft spring may be entirely eliminated and it is only necessary that a predetermined minimum tension be placed: upon all-the springs 12 of a set of grippers in order to insure entire satisfactory operation of the device. The fact that some of the springs may be at g ater thanthe minimum tension so as to compel their appropriate gripper fingers to seize the sheet with more than necessary force, isof nofmoment due to the fact that in our improvements lack of exact adjustment of one finger does not react upon the other fingers as in the devices now in use. Any springing of the shafts by the pressure of the fingers is eliminated by the fact that such pressureis neutralized by the counterpressure of the springs'upon the saddle shaft through fulcrum plate 8. The arrangement is such that the springs act equally upon the fingers and the saddlesha-ft, tending to move them toward each other.

Having described: our invention what we claim and desire to secure by Letters Patent is as follows:

1. Gripper for mechanism printing 1 resses com )risin a 'ri 3 )er shaft. a ri 7 b b K:

per. finger loosely mounted on said shaft, an actuating sleeve for said finger, a saddleshaft, an actuating'spring for said gripper finger and means carried by the saddle-shaft and engaging the spring whereby the action of said spring will tend to move the finger and saddle-shaft toward each other.

2; Gripper mechanism for printing presses comprising a gripper shaft, a gripperfinger mounted on said shaft, a saddleshaft, a fulcrum plate on said saddle-shaft, and a spring reacting against the fulcrum plate and connected to the gripper linger, said spring beingadapted to move the gripper linger toward the saddle-shaft.

In grippers for rinting presses, a gripper finger formed with a partially circular base adapted for mounting upon a gripper shaft, an actuating sleeve for said gripper finger, a lever arm connected to the gripper finger, a iinlt rod com cted to the lever arm, and a sp ing upon the link rod and adapted to more said rod lengthwise against the resistance of a member of the press.

Gripper mechanism for printing presses comprising a gripper linger adapted ror mounting on a; gripper sha rt, an actuating sleeve adaptedtobe fixed to the gripper shaft and having a shoulder for engaging the gripper linger, a lever arm connected to the gripper finger, a link rod connected to the lever, a fulcrum plate having an aperture adapted to receive the link rod and adapted to be secured to the saddle shaft of a press, a spring surrounding the link rod intermediate its free end and the fulcrum plate, and an adjusting member carried by the link rod and adapted to adjust the tension of the spring.

5. In printing press feed mechanism comprising a gripper shaft and a saddleshatt, a gripper finger adapted for oscillation upon the gripper shaft, a device for actuating the finger, and spring acting means adapted to sin'iultaneously impose pressure upon the gripper finger in a direction toward the saddle-shaft and pressure upon the saddle-shaft in a direction toward the gripper finger.

In testimony whereof, we have signed our names to this-specification.

WILLIAM GEGENHEIMER, V ERNEST n. BARNEY. 

